A variety of assays make use of hydrogen peroxide as an intermediate for indirect analysis for a target molecule. For example, glucose may be measured by using glucose oxidase to produce hydrogen peroxide and using the hydrogen peroxide with a peroxidase to oxidize a substrate and produce a detectable signal, such as a color change. Examples of such oxidizable substrates include Amplex Red (Invitrogen) and PS-ATTO (Lumigen). There is a need in the art for approaches to miniaturizing and/or accelerating hydrogen peroxide assays.
Droplet actuators are used to conduct a wide variety of droplet operations. A droplet actuator typically includes a substrate associated with electrodes arranged to conduct droplet operations on a droplet operations surface of the substrate. Droplet actuators may also have top plates, which are generally separated in a parallel fashion from the droplet operations surface, forming a gap in which the droplet operations may occur. The gap may be filled with a filler fluid that is immiscible with the fluid that is to be manipulated on the droplet actuator. There's a need for expanding the capabilities of droplet actuators to include hydrogen peroxide based assays.